Nonfimbrial Adhesin Mutants Reveal Divergent Escherichia coli O157:H7 Adherence Mechanisms on Human and Cattle Epithelial Cells

Figure 6

SS17 adherence mutant phenotypes on RSE cells. The parental strain and the adherence-associated gene mutants of SS17 were tested for adherence quantitatively (a) and qualitatively (b) on RSE cells. As the results show, none of the mutations significantly altered SS17’s ability to bind RSE cells with its distinct aggregative, strong adherence. (a) Each bar is representative of four technical replicates per slide where 20 cells/spot were counted over two trials. The bar is the mean percentage of adherent bacteria (>10 or 1–10) per RSE cell over the two trials. (b) Immunofluorescence of SS17 adherence pattern on RSE cells. Bacteria are labeled with green, RSE cell cytokeratins with red, and RSE cell nuclei with DAPI (blue) fluorescent staining. The scale bar for each panel is set to 100 μm and the white arrows show the O157 on RSE cells.

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(b)